1. Field of the Invention
The invention is related to the field of telecommunications, and in particular, to a software interface product and method utilized between a telephony card and a digital communications network.
2. Background
Advanced communications networks are being developed to support a vast array of communications services. These networks are controlled by complex hardware and software platforms referred to as session managers. Users requiring communications sessions from these advanced networks must interface with the session managers to request and receive communications services. Session managers operate using various messages, such as invite messages, reply messages, confirm messages, join messages, and terminate messages.
A class 5 telephone switch communicates with an analog telephone using the analog telephony signals in the well-known analog telephony format. The class 5 telephone switch provides power to the telephone. The class 5 telephone switch detects off-hook current caused by the telephone and provides the telephone with dial tone. The caller generates Dual-Tone Multi-Frequency (DTMF) signals. The class 5 telephone switch detects the DTMF signals and initiates the call in the network. When the far-end telephone is ringing, the class 5 telephone switch plays a ringback tone to the caller. If the far-end telephone is busy, the class 5 telephone switch plays a busy tone to the caller. On incoming calls, the class 5 telephone switch provides ring current to the telephone.
Telephony cards are being developed to manage multiple telephones in the home. The telephony cards are typically plugged into communications hubs or computers in the residence, and telephones are connected to the telephony card. The telephony cards connect these telephones in the home to a network element in the advanced communications network. This connection between the telephony card and the network element is much different than the traditional analog line to the local switch. This connection is typically an Asynchronous Transfer Mode (ATM) connection to an ATM device. ATM signals do not traditionally support analog telephony signals, such as off-hook, dial tone, and busy signals. The telephony cards detect off-hook conditions, on-hook conditions, and digits. In addition, the telephony cards provide the telephones with dial tone, ring current, ringback, and busy signals.
At present, there is not an acceptable software interface method or product for use between the telephony card and the session manager in the network. There is a need for software that can provide an interface between the telephony card and the session manager.